The primary objective of the proposed research will be to continue with the analytical phase of our studies of the man-biting activity of haematophagous Diptera in a Neotropical rain forest environment. The field aspects of the study have been completed and were conducted in a remote region of north central Colombia, South America. We have recently completed the portion of the study concerned with the man-biting activity of phlebotomine sandflies and a manuscript of this work is attached to this proposal as an appendix. The methods of data analysis to be used are described in this appendix. During the period of the proposed research, we intend to analyze the data that we accumulated on the man-biting activity of the Simuliidae Tabanidae, and Culicidae at our study area. The results will then be prepared for publication. The aspects of biting activity emphasized in our study include diel periodicity, vertical stratification, seasonality, and differences between the forest and clearing habitats and between the various microenvironments within these habitats. Some time will be devoted to a taxonomic study of a small tabanid subgenus, Amphichlorops, and to some unresolved mosquito identifications. The ultimate goal of our study is to obtain a comprehensive description of man-biting activity by all of the bloodsucking Diptera of a delimited area of Neotropical rain forest. This will allow us to look at interfamily relations in biting activity such as possible partitioning of time and microenvironments.